From what I’ve understand from the Chinese news (translated from Korean news):
1. Seoul Police is investigating a case of people smuggling drug from Japan, it involves a female TV artist and a male model.
2. The female TV artist is suspecting to have start smuggling drug back in August 2007, went to Japan for 14 times and bought almost 1 million Korean won of drugs (280 pills of ecstasy and other drugs). She smuggled her drug using her underwear. Then she would sell the smuggled drugs to other people, including the male model.
3. According to the police investigation, Joo Ji Hoon, who knew the artist, have used marijuana twice with the artist around Mar 2008. (according to the news report, he has admitted it)
4. Even though this is not the first time that artists have been found to be involved in using drugs, this is the first time that police have a case where the artist bought the drugs from overseas and smuggled the drugs into the country.
5. As the news broke out in Japan, Joo Ji Hoon’s film, Antique, was pulled from the theaters earlier than planned. The schedule release of his next movie, Kitchen, on 30th May have been postponed. The planned movie, Tokyo Tower, have lost sponsorship so the future of that film is now hanging.
Source: Compiled from various translated Chinese sources from SINA / brief summary English translation from fangorn @ reikanorakuen.wordpress.com